Cita APA

Haffer, J. H., & Borrero, J. I. (1965). On birds from northern Colombia.

Chicago Style Citation

Haffer, Jürgen H., i José I. Borrero. On Birds From Northern Colombia. 1965.

Cita MLA

Haffer, Jürgen H., i José I. Borrero. On Birds From Northern Colombia. 1965.